A comprehensive review of solar facades. Opaque solar facades

In antiquity, people already knew the principles of solar architecture, designing their houses to the south to take advantage of the sun in all seasons. Today, solar architecture is undergoing a true revolution because of the development, among other things, of special facades involved in the processes of heating, ventilation, thermal isolation, shading, electricity generation and lighting of homes: these are called “solar facades”. This paper aims to review the remarkable developments that have occurred during the first decade of this century in this field.     

ϵ‐caprolactone grafting on a poly(vinyl alcohol‐co‐vinyl acetate) in the melt without added initiator

Polycaprolactone (PCL) grafting on vinyl alcohol‐co‐vinyl acetate) (PVA‐Ac), was investigated in the melt at high temperature (170°C), below the PVA‐Ac melting point, by ring opening polymerization of ?‐caprolactone initiated by metal alkoxyde sites present in PVA‐Ac: no additional initiator was used. The obtained average structures were determined by ¹H NMR. As expected, small grafts, with low average polymerization degree (DP), were obtained, between 4 and 12 h of reaction. These DP are due to exchange reactions between hydroxyl groups and PCL growing chains. The PVA‐Ac was shown to be partially substituted by short PCL grafts. The DP linearly increased with the initial Lactone/PVA‐Ac ratio, and the substituted alcohol sites rate were limited to 63%.It was shown that the used reactive system is characterized by a quazi‐living polymerization mechanism. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

On the effect of the orientation of sheet rolling direction in shot peen forming

Peen forming is commonly used in the aerospace industry to shape large and thin panels, such as wing skins. This manufacturing process uses shot peening to introduce unbalanced compressive stresses near the surface of the component. These stresses tend to bend the panel and, when optimized, lead to the desired contour. Sheet materials often exhibit both elastic and plastic anisotropy, which can alter the development of curvatures. Since peen forming relies on compressive stresses to upset equilibrium, resulting curvatures may also be affected by initial stresses in the part. In this work, the influence of the rolling direction orientation with respect to the sample was investigated experimentally and numerically for the first time for aluminium alloy 2024-T3 specimens. Although maximum deflections were only slightly dependent on the rolling direction orientation, it was found that radii of curvature varied by as much as 10% with respect to this parameter. Finite element simulations allowed quantification of the individual effects of non-equibiaxial initial stresses and elastic orthotropy. It was found that these factors can significantly influence curvature development. Comparison of experimental and numerical results suggested that plastic anisotropy should also be taken into account in future studies. The tools developed in this study show promises for the accurate prediction of peen forming process for large scale components.     

The effect of drinking milk containing conjugated linoleic acid on fecal microbiological profile,enzymatic activity,and fecal characteristics in humans

Background  

The primary objective was to determine whether consumption of conjugated linoleic acids (CLAs) affected the fecal microbiota composition, fecal enzyme activity or fecal composition.     

Antimicrobial effect of natural preservatives in a cooked and acidified chicken meat model

The inhibitory effect of Microgard 100, Microgard 300, nisin, Alta 2002, Perlac 1902, sodium lactate and essential oil of mustard on microorganisms experimentally inoculated was screened in an acidified chicken meat model (pH = 5.0) and stored for 2 weeks at a none restrictive growth temperature of 22 degrees C. All antimicrobials tested were used at the highest concentration recommended by their manufacturer. Sausage batter made with mechanically deboned chicken was inoculated with a mixed culture of Escherichia coli ATCC 25922, Brochothrix thermosphacta CRDAV452, and a protective culture Lactobacillus alimentarius BJ33 (FloraCan L-2). A final cell concentration of 3-4 log CFU g (-1) was targeted after cooking at a core temperature of 55 degrees C for each microorganism in order to assess cell count variation effectively. Composition, water activity (a(w)), pH and redox potential of the sausage model was also evaluated. The E. coli population decreased steadily during storage and was close or below detection level (< 1 log CFU g (-1)) for all treatments, including the control, after 14 days. Sodium lactate was most effective against B. thermosphacta; population was 4 log lower than the control after 14 days of storage. When essential oil of mustard was used, aerobic mesophilic bacteria and lactic acid bacteria were significantly lower than the control after 2 days of storage (P < or = 0.05). The other antimicrobial agents tested had no significant effect on the aerobic mesophilic bacteria, E. coli, B. thermosphacta and lactic acid bacteria counts, when compared to the control.     

A measurement framework for object-oriented software testability

Testing is an expensive activity in the development process of any software system. Measuring and assessing the testability of software would help in planning testing activities and allocating required resources. More importantly, measuring software testability early in the development process, during analysis or design stages, can yield the highest payoff as design refactoring can be used to improve testability before the implementation starts.

This paper presents a generic and extensible measurement framework for object-oriented software testability, which is based on a theory expressed as a set of operational hypotheses. We identify design attributes that have an impact on testability directly or indirectly, by having an impact on testing activities and sub-activities. We also describe the cause-effect relationships between these attributes and software testability based on thorough review of the literature and our own testing experience. Following the scientific method, we express them as operational hypotheses to be further tested. For each attribute, we provide a set of possible measures whose applicability largely depends on the level of details of the design documents and the testing techniques to be applied. The goal of this framework is twofold: (1) to provide structured guidance for practitioners trying to measure design testability, (2) to provide a theoretical framework for facilitating empirical research on testability.     

Optimization of the process of drying of corn seeds with the use of microwaves

Abstract

The heating and drying of various types of food using microwave improve the economy of time and energy. The physiological quality variation of the seeds submitted to microwave drying is known to some extent. In this context, some authors have reported excellent performance using this technique, on germination rates, after drying. The commercial use of microwave drying in seeds is irrelevant, which motivates more extensive research on the benefits and challenges of this technique that can increase its insertion in the post-harvest handling steps of agricultural products. Corn is a product of high worldwide relevance. Therefore, the use of microwaves in its drying process has excellent potential to arrive at significant savings in its production. Thus, this study is aimed to evaluate the effects on the physiological quality of the seeds submitted to different drying conditions, using the microwave radiation. To that end, corn seeds, with a water content of 20% on wet basis (w.b.), were dried at 40, 50, and 60?°C, at power ratings of 0, 0.6, and 1.2?W/g; in the vacuum condition. Drying occurred continuously, with intermittent power, until the seeds reached the 12% wet basis; in this condition, the seeds could be stored with secure. Germination tests performed shortly after drying showed that the temperature of 40?°C at a power of 0.6?W/g had a reduction in drying time of approximately 5?h when compared to conventional drying (40?°C and 0.0?W/g). The evaluation of the physiological quality of the seeds showed no significant difference in the germination, vigor, and longevity indices of the treated seeds.     

Precipitate formation contributing to sump screens clogging of a nuclear power plant during an accident

For many years, the French “Institut de Radioprotection et de Sûreté Nucléaire” has developed studies concerning chemical effects, which can occur during a loss of coolant accident (LOCA) on a nuclear power plant, due to precipitate formation leading to an increase of head loss to sump screens. This increase can cause the loss of emergency core cooling system (ECCS) and of the containment spray system (CSS), which are the two removal heat safety systems which ensure the accident mitigation.These precipitates are formed by recombination of mineral species, which are released due to corrosion of immersed debris (particles of concrete, glass fibre insulation, piece of paint…). PHREEQC software has been used to identify nature and mass of precipitates that can be formed during a LOCA.This report presents the results of sensitivity studies carried out with PHREEQC. Chemical precipitate formation is studied as a function of several physical parameters, such as temperature, pH, nature and debris concentration. The optimal conditions in order to reduce the formation of precipitates are drawn from these calculations.     

Quantifying errors in spectral estimates of HRV due to beat replacement and resampling

Spectral estimates of heart rate variability (HRV) often involve the use of techniques such as the fast Fourier transform (FFT), which require an evenly sampled time series. HRV is calculated from the variations in the beat-to-beat (RR) interval timing of the cardiac cycle which are inherently irregularly spaced in time. In order to produce an evenly sampled time series prior to FFT-based spectral estimation, linear or cubic spline resampling is usually employed. In this paper, by using a realistic artificial RR interval generator, interpolation and resampling is shown to result in consistent over-estimations of the power spectral density (PSD) compared with the theoretical solution. The Lomb-Scargle (LS) periodogram, a more appropriate spectral estimation technique for unevenly sampled time series that uses only the original data, is shown to provide a superior PSD estimate. Ectopy removal or replacement is shown to be essential regardless of the spectral estimation technique. Resampling and phantom beat replacement is shown to decrease the accuracy of PSD estimation, even at low levels of ectopy or artefact. A linear relationship between the frequency of ectopy/artefact and the error (mean and variance) of the PSD estimate is demonstrated. Comparisons of PSD estimation techniques performed on real RR interval data during minimally active segments (sleep) demonstrate that the LS periodogram provides a less noisy spectral estimate of HRV.